基于虚拟同步策略的电动汽车V2G技术在多能互补系统中的研究及应用

为解决大规模电动汽车单向充电造成的电网冲击和线路负荷过重问题，开展了电动汽车V2G技术在多能互补系统中的应用研究。首先，对比分析了多种典型的多能互补系统拓扑结构的技术优缺点，在基于共交流母线的多能互补系统中应用V2G技术。其次，提出基于虚拟同步机的V2G自主有功-无功控制策略，优化设计虚拟惯量、阻尼系数等关键参数，模拟传统发电机组的机电暂态特性，实现系统自主调压调频，解决光伏发电的间歇性和随机性带来的电网指标波动问题。然后，搭建了典型的多能互补系统，并进行仿真验证。结果表明，基于虚拟同步机的V2G设备能主动跟踪并网点频率、电压变化，及时提供有功、无功功率支撑，有效保障电网运行的稳定性。最后，研制了基于虚拟同步策略的500 kW大功率V2G设备，并在示范项目中成功应用，验证了所提方法的有效性。

Research and application of electric vehicle V2G technology based on a virtual synchronization strategyin a multi-energy complementary system

There are problems of power grid impact and line overload caused by one-way charging of electric vehicles on a large scale. Thus research and application of electric vehicle V2G technology in a multi-energy system are carried out. First, the technical advantages and disadvantages of several typical multi-energy system topologies are compared, and V2G technology is adopted in a multi-energy system based on a common AC bus. Secondly, an autonomous active and reactive power control strategy for V2G based on a virtual synchronous machine is proposed to optimally design key parameters such as virtual inertia, damping, etc., simulate the electromechanical transient characteristics of traditional generator sets, realize the independent voltage and frequency regulation, and solve the problem of grid index fluctuation caused by the intermittent nature and randomness of photovoltaic power generation. Thirdly, a typical multi-energy system is established for simulation, and results show that the V2G equipment based on a virtual synchronous machine can actively track the changes of frequency and voltage at the connection point, and provide active or reactive power support in time. This effectively ensures the stability of power grid operation. Finally, a 500 kW high-power V2G equipment based on the virtual synchronization strategy is developed and successfully applied in the demonstration project, verifying the effectiveness of the proposed method.This work is supported by the National Key Research and Development Program of China (No. 2019YFE0118700).